We live in an era of unprecedented automation. Whether it's building your next car or assisting in your next surgery, robots have become an indispensable part of modern society. It's no surprise, then, that robots are also doing work in space. But, unlike here on Earth, astronauts can't just call a mechanic when something goes wrong.
Enter the era of robots repairing robots. The star here is Dextre, a Canadian-built robotic manipulator. You might not immediately think of Canada when you think of space, but in space robotics, they are second to none. In fact, both Dextre and the robot it was repairing, Canadarm 2, were commissioned by the Canadian Space Agency.
Why use Dextre to repair the Canadarm 2? Unlike a terrestrial repairman, who can just drop by for a few hours to get the job done, sending astronauts on a spacewalk is a much more involved operation. Not only does it entirely consume the attention of the crew for the duration of the repair, but extra-vehicular activities must be meticulously planned before anyone even enters an airlock. Nothing is more important than human safety and so nothing takes longer than actually sending humans out into space.
Contrast that with the current operation. Dextre is replacing an old camera attached to the Canadarm 2 with a backup and replacing another completely broken one with the old one. How much do the ISS astronauts need to do? Almost nothing: the only action required of them was to place the backup camera into the airlock. Dextre then opened the airlock, retrieved the camera, and began using its tools to make the exchange.
So, does this mean that spacewalks are a thing of the past? Not so fast. Although I'm sure NASA would love to eliminate astronauts leaving the ISS entirely, we've still got a ways to go. For one, Dextre can only manipulate and repair objects specifically designed to be robot friendly. Normal bolts and screws will simply leave it stymied. Dextre is also limited to working on places reachable by the Canadarm 2.
Even with these limitations, it is clear that the future of repair in space lies with robots. As our missions become longer and more complex, offloading tasks to robots will offer the same benefits today that offloading tasks to computers did in decades past.